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Patent Filing & Litigation

The Pitfalls of Overly Broad Patent Claims

Patent claims are among the more important sections in a patent application and form the basis of its novelty and scope. These technical descriptions are at the heart of a patent’s legal protection and have important strategic and legal implications for patent holders. For years, broad patents were favored by inventors and patent agencies like the USTPO. However, a shift has occurred, with successful patents now including narrower claims. A number of factors should determine the appropriate broadness of your patent claim, including the industry, existing prior art (including technology active in the marketplace), and strategic objectives. If application claims are too broad, they are subject to a number of rejection risks.

Claim Broadness

To better understand the issue of claim broadness, a basic definition is needed. Claims define the boundaries of an invention and establish its expected impact–i.e. what problem it purports to solve. Therefore, the ‘broadness’ of a claim is related to the scope of the invention: what technical areas it covers and what kinds of effects the invention has.

A simple but apt hypothetical example: A traditional combustion engine made for a car does not preclude someone from patenting a car engine powered by electricity. While both power cars, their unique technical modes of doing so make them different inventions.

Conversely, a combustion engine lightly modified to power an airplane might still be covered under the original patent for cars. But a more heavily modified combustion engine could receive a separate patent for both the plane and perhaps even the car, but for different reasons. So in crafting the original combustion engine claim, going broader might attempt to anticipate future innovations and their technological specifications. The scope of a combustion engine would almost certainly not cover all forms of propulsion simply because they make a plane, car, or boat move.

Why Broad Can Be Bad

In the above example, the combustion patent illustrates why broadness—or narrowness, as the case may be—is so important to patent application quality. The author must decide how much of a technical space they want to capture with the basics of a combustion engine. Even though it’s central to the design, the actual phenomenon of combustion occurs in nature and is therefore not patentable. So the scope of any hypothetical patent would choose varying degrees of technical and impact-based claims separate from its combustion activity. How does the engine harness and displace energy? What materials does it use to do so efficiently and safely? These questions would be central to any claim.

Let’s examine the risks and strategic implications of these choices. While there is value in broader claims, like preventing competitors from making small tweaks to inventions overtaking the marketplace, there are also risks to this approach.

Broadness and Risk Exposure

Overly Broad Claims

An inventor should strive to accurately represent their invention and its technical achievements within claims. The description, glossary of terms used, and the prior art referenced can all on their own lead to claim scrutiny along the three key dimensions of a claim: novelty, usefulness, and non-obviousness.

Broad claims are at risk of rejection in part because the patent examiner cannot properly evaluate the claim’s accuracy. This risk can also be described in opposing terms: the claim lacks sufficient narrowness. As a result, the patent examiner cannot properly assess the novelty or scope of the invention and its description.

Whereas overly broad claims can misrepresent what technical specifications an invention includes. When asserting that an invention occupies more technical space than is the case, the examiner will not be able to truly assess what differentiates your invention from others. Broad claims tend to rely on a higher degree of abstraction and scientific concept. This may be the case in instances where claims are made based on their outcomes or effects.

The risks of this strategy are best illustrated in a case recently added to the Supreme Court docket: Amgen vs. Sanofi, which demonstrates the theoretical effects of a biologic drug on human tissue and can not account for its mechanism of action. A reliance on broad claims in the form of abstractions violates several tenants of a quality patent including its replicability and novelty. Your claims must reflect an innovation that can be duplicated by those in your field. Lackthereof is grounds for application rejection.

Additional Concerns

More Overlapping Prior Art

It follows that the broader your claim the more prior art it could potentially encompass. This is one of the strategic considerations one must recognize when determining how broad their approach to patenting will be. Prior art is therefore an opportunity and a risk.

It is the task of the application preparer to compile the most relevant prior art. This helps the patent reviewer understand the patent landscape in order to evaluate your application. They are actively using the prior you supply to evaluate your claims, their novelty, and their usefulness. However, prior art can be a source of rejection. Including unnecessarily broad claims and attempting to establish those claims with a larger body of prior art creates additional opportunities for examiners to find claims non-differentiated or lacking novelty.

Tools are available to preemptively assess how difficult differentiating your invention may be.’s software suite and prior art database (PAD) can help identify and visualize the competitive landscape within a given technological space.

Difficult to Enforce

Additional strategic consideration beyond patent application approval impacts how broadly to write claims. These include future enforceability. As we’ve seen in recent years, the definition of enforceable invention claims is always changing. And while ideally, an approved patent application should mean that the claims are also enforceable by the patent holders, shifting laws and norms could impact this.

Patent preparers must consider not only whether an application can be accepted in comparison to current prior art but whether these claims will hold up in a dynamic and sometimes unclear legal environment. Additionally, your claims may not only be difficult to enforce but attract more litigation. So even if you are able to successfully defend your patent in court, the cost of doing so may erode its monetary value.